Web-heating device



0d i6, 1951 K. l.. DIETRICH WEB HEATING DEVICE 2 Sheets-Sheet l Filed April 27, 1948 :Inventor KARL. I.. DIETRICH Y Gttomeg Filed April 27, 1948 n K. L. EDIEITRICHv WEB HEATING DEVICE 2 Sheets-sheet 2 L i DIE Bnventor TRI CH (ttorneg Patented Oct. 16, 1951 WEBS-HEATING.' DEVICE KarliLz. Dietrich;- .Rliiladelplar Pai, assignon to Sela's Gorporationf.` of American-5v Philadelphia; Pa a corporation of Pennsylvania ApplicationApril 27, 1948; Seral'No.- 23,565*y Claims; l'.

The present inventionlrelatesto the tre'atIm-mtv ofa'continuously moving weblof material.,byrheatr sucl'r asy the drying-*off inklfon/a a' printed.: web on the 'singing"of"'a-text1= web, 0rfor:i other-Spule poses: The inventionwill'be describedfhereirrin connection with thedryingf'off ink`A on..a...printed web vsince vthat 1is a'-usual 'application .to :which apf+ paratus of thisetypemayf--be placed: It should be understood;I however; that the described appli*- cati'on'isonly oneexample" of whererthe". device may-113e used.

In color printing -in=modern -web Vpresses .the web is ist' given' oneimpression'- and thenidried :before passing directlyto Lreceive f aI second J impresel sion.- Thevdryingmustltake place. inaa Short periody ofYtiine-andfwhil theiweb is-:movngfat a relatively highspeedf Duringthefdrying opera--` tion, asl well= as-duringeth'e printing;.care must be exercised to maintain-theI web .underscona stant. tension z acrosscaits entire f widtlrto lreduce thetendencyfor aaweb break; Thee-tension:y of thefwebalsoenterstinto;.therproblemlof-imaintain ingria constant lengthaof web between each pair of impression: rolls, -fso l. that" i proper .register oc. curs. when. two.. orcmoref-colors'fare being..used. Withthe many problems encountered. in handling the webzitse1f;.has.1 been added` that...of. placing. drying ovens. in .thepath of Web-travelV between the. .pairs:onimpressionrrolls: The ,dryers-.heretofore-:used require ai large f-amountmf' .-space `in .a relativelyjcrowdedsarea;r They. also .makeit difiicult'.A to '..thneadz ,the:press^,. and? particularly-A.. so whenv a webzvbneakxoccurslafter thefdryers have been in;use;1. Sincef'thef web `p assessthroug'h the oven".v iny proximity-g to: thee burners thereof..v there is .always thea danger lof asirev when the. press .is stopped.A

Withthe. dryer of the. present yinvention pro vision is made -to move: theV .web :.into and .out of thef'ovenfas .the-pressisbeing started and stopped. The; arrangement. is :such thatv` the l1ength:of...the weby .is notaltered',Y `andethe tension. ofthe vwelcfis not variedfasfthe .movinggthereof-is taking place. Thefoven that is. used. with thepresenainven: tion dau-shaped; and. therefore. does .not require as muchroom theV press as does theconven tional Joven.` The. ventire ,dryer assembly. corn.- pact and. may easily be.- p1aced..between-groups.of impression rollers.:A

Since the-.Webis moved out of..the.oven;` when the press is .stopped or.. when aweb break` occurs the dikelihood of. a .Vreis .reduced .to..a..neg1igble extent, Y Also, .thev dimculty; of rethreading.the preSsater.a.-web..break is .reduced sincethe..op,. eratorsr-.dofnothave ...to .pass .the..web. through '..a hot-ov.en..y

It-.isannobj'ectlof the'inventioni to 1 provide ra w'ebldryer :ini .which thefwebv may `-be moved:e into andiout of 'the ovenLthereof either-.automatically inf responseV tooperationuof the: machine.' with" which'theldr-yer isbeingused',or manually.; It` is a' further robject: ofitheinyention to provide' 1a. web-dryer in" whichithe web.may..be: moved' to and; from the.. oven. thereof? without'. altering.- ther tensionziofl the. web 101.'. theslengtli: of; thee wehren-sf tending Lbetween l operatingepants Lof. the .machine withwhichtheidryer islus'edl It .is a.f.urther'.`object ofi the'fiuvention toiprovideabweb dryer` throughzwhichzthe'.webmaysbe easily and .conveniently threaded, and?.y one-'iny whichJ their'e l'iaz'ardiis'Lgreatlyreduced.1

It''is la..furtherobjectfcofizthe invention; toi; proef vide a method of drying a movingfweo. The methodlcomprisesamnving;.thewebzintorandroutof a heating zone im accordant:e;awth..various' opere atingacond'tionsointhemachines.thatf .is operate: ing on=A t1 ie4web` Ituristafurthenobjectfofth invention tofpr'oe vide amethod;ofishiftingealweb.=into;.and outlof a. heating zone. without:` altering; its length:or varyinglits tension..-

The fvarious; featuresiiof: novelty. whichrchare acterizeemiy :invention .are'xpointedioutwithwpare ticula'rityain; the: claims.. annexedto and-:forming aanarttof this1snecifi'catiom- For :azbettersiundere standing @father inventiom. however; its Sadi/ane` tagesrands'specicr..ohiectsxattained withcits use? referencer; shouldav bef. had; to the accompanying drawings; and; descriptive; matter-,in whichilzhav'e illustrated. aud'zdescribed a..preferred.:,emb0diment of the inventiom.

In: the :drawings z Eigure'fl is aeviewzshowingithe entire dryer fasi; sensibly withl;y thezcontrol. valvegincsection ;v 5

Figure; 2 1 is :a ViewI taken. on.: line. 2-2 or Eig. urezl.;

Figure f3 is-I a; View taken aan .lline :3e-3. oli-Fig-y ure.1;.. 1

Figur e141v is a diagrammaticview oifadi1erent embodiment of the invention; and

Figure 51.iswapartialfviewpf another. embodimentnf the' invention.

Forf purposes ofthe.- presentrdescription.. vthe applmts dryngfdevice. .is described. as` being usedv in. .connection..with a .printing., press. to.. dry ink... that has .been I@Laced-.upon a continuously moving-5 web.V In.Figure.1 thereearefshowncross pieces I.. of. a-press.that.are;.separated by .a ver:- ticalpostZ. The dryingdevice is=mountedontlie pressb'etween thecross pieces 1.1' The. web'W is' broughtinirom. aboveas indicatedfatand passes inoneloparounda roller 4 and'in another loop around a roller 5. Both rollers are mounted on a movable carriage 6. From roller the web is led around water cooled rollers I and 8 where it leaves the device at 9 on its way to another pair of impression rollers to receive additional ink or to some other part of the press.

In its path through'the drying device, as it moves` around roller 4, the web passes through an oven I I that supplies the heat to dry the web.

Carriage 6, mentioned above, consists of a pair of side plates I2 and I3 shown best in Figures 2 and 3 that are suitably joined together so that they move in unison. The carriage and the rollers 4 and 5, mounted thereon, are moved in a vertical direction to carry the loop of web into and out of the oven depending upon whether drying is to take place or not. In order to guide the carriage as it moves through the oven there are provided four guide rolls I4 located in pairs on each of the side plates. These rollers move vertically in tracks I5 that are attached to structural' steel members I6 which form the framework for the entire device, best shown in Figures 2 and 3. The rollers I4 are mounted in bearing supports II which are, in turn, located on brackets I8 fastened respectively to the side plates. Thus the entire carriage is guided by eight rollers, four on each end so that it may move vertically in the tracks I5 to move the web into and out of the furnace. It is noted that the water cooled rollers 1 and 8 are mounted in bearings I9 and 2|, respectively, which are attached to two structural members I6. These latter members, of course, are stationary so that the water cooled rollers remain in a fixed position relative to the other parts of the press.

It is essential that side plates I2 and I3 move exactly the same amount in order to prevent the rollers 4 and 5 from being tipped so that the web has more tension placed on one edge than on the other. To insure that the carriage moves absolutely vertically, there is provided a shaft 22 which has pinions 23 on each end of it. These pinions mesh with the teeth of racks 25 which are attached to one of the vertical structural members I6 on each side of the device. The shaft 22 is journalled in bearings 26 that are mounted on brackets 2l, one of which is fastened to each side plate I2 and I3. Thus, as the carriage is moved in a lvertical direction, the pinions roll upY and down the racks 25 to insure that both sides of the carriage move exactly the same amount. The same brackets 2l upon which bearings 25 are mounted are used to support bearings 29 for a shaft 28 upon which the roller 5 is mounted. Thus, the roller is mounted so that it can rotate in bearings which move along with the carriage. Roller 4 is provided with a shaft 3I, as shown in Figure 3. This shaft extends through the side plates I2 and I3 where it is journalled in bearings 32 that are mounted on brackets 33 which, in turn, are fastened to the respective side plates of the carriage.

4 the piston rods move downwardly to move the carriage to the position shown in Figure 1, with the web in the oven. When fluid is admitted through pipe 4I the piston rods are moved upwardly to move the carriage upwardly and carry the web out of the oven. When this occurs the rollers 4 'and 5 take the position shown at 4 and 5 respectively. It will be noted that the roller 4 is then above the top edge of the oven and out of the heat that is produced by the oven.

Referring now to Figures 1 and 3, it will be seen that the oven is U-shaped and includes two panels 42 and 43 which are mounted on opposite sides of the roller 4 and joined at their lower ends. Each of these panels is provided with a series of burners of a type, for example, similar to those disclosed in detail in Hess Patent 2,215,079, granted September 17, 1940. Each of these burners is supplied with a combustible gas mixture through a tip 45 that extends into a cavity 44 of the burner. As the gas Vis burned in these cavities the surface` of the cavities are heated to incandescence to supply radiant heat to the web as it is moving past them. It is noted that each of the tips 45 is supplied through a pipe 46 which is connected to a 'manifold 4l. Each of the pipes 46 is provided with a valve 48 so that the burners can be adjusted individually to give the desired pattern of heat over the web. For example, if a narrow web is being fed through the press, it will only be necessary to use those burners facing the web. The other burners may be turned off and thus' save fuel and reduce the likelihood of overheating of the web. It will be seen that the radiant panels or the sides Yof the oven are separated by slots 49 and 5U respectively through which shaft 3| of roller 4 moves as-it is shifted to bring the web into and out of the oven.

Manifolds 4j1 supplying the individual burners are in turn supplied by a pipe 52 that has in it an automatically controlled valve 54 around which is placed a by-pass 55 having a manually controlled valve 56 in it. In the normal operation of the oven, when the press is running, valve 54,

The carriage is shown as being moved in a ver- H tical direction by a fluid means, To this end cylinders 34 and 35 are mounted on the framework of the device, one on each side of the carriage, as best shown in Figure 2. The cylinders are provided with piston rods 36 and 31 respectively, which extend downwardly and are attached to the side plates. One such attachment is shown at 38in Figure 1. Fluid is supplied to the opposite ends of the cylinders, as best shown in Figure 1 by means of. pipes 39 and 4-I respectively. When fluid is admitted through pipe 39 f the other of cylinders 34l and 35.

which is shown as being a solenoid valve, is energized to open pipe 52 so that the combustible gas mixture may flow to the burners. The energizing circuit for valve 54 is connected in any suitable manner with the energizing circuit for the press itself so that when the press is running valve 54 is open. When however, the press is stopped for some reason, 'valve 54 will be de-energized to shut off the supply of gas and cut down the heat of the oven. This prevents overheating of the oven when'no webis to be dried, and acts as a safety control to insure that overheating will not take place. During the time valve 54 is closed a certain predetermined amount of fuel can pass through thevalve 56 to keepv the oven at a minimum desired temperature. Since the burnersare kept running at a low rate it will prevent the oven' from cooling down entirely;Y therefore when the press is re-started and the fuel gas supply is passed to the oven, the oven will heat up and be in condition to dry the web by the time the web is moved into the oven.Y It is noted that an exhaust duct 60 is provided at the upper ends of each heating panel 42 and 43 so that the exhaust gases from the oven may be drawn off before they can overheat the other parts of the dryer.

As noted above, carriage 6 is moved in a vertical direction to lbring the web into and out of the oven by' the admission of fluid to one end or In Figure 1 there is illustrated a valve arrangement whereby tl-ie-.flow-pil fluid to-.theopposite ends .of fthe-cyl` inderswan-be contro1leda= The.upper-end'.ofb'otlr.v

cylinders`V 34". and 35i. will be. supplied :by pipe 3% whereas. thelower end` of both- .cylinders will be` suppliedrv by pipe-Jil?.v There isf-shown a. pistonl type valve-'l-which is suppliedwithiluidf-under. pressure .through an inlet: 58.". 'I-hervalvechamber.v has locatedinit a pistonrod :59'on which are placed pistons `vEi-l and 6:2: Thepiston valve .may loe-heldV -in its-upperposition against theforce of-acompression springy 631 bya solenoidi'corelk whichiscontrolled? by-a solenoid-65: When -1 intliis-upperposition,as shown in thegdrawingl-Dipe- 39h-is connected` with supplypipe 58 and-:pipezlll;y is connected with the exhaust through-a--throttle valve 61. When` the piston Valve is moved downwardlypipe-HA is connected-with supply 58-and pipe 39-is connected `with the exhaust through athrottle valve 66.' Valves-66 and 61'!` are used -intheexhaust lines to control the speedof-movement-fofl the piston.A By adjusting these valves to control the-rate at which iluid may be 'exhausted' from the piston the rate ofmovement; of'- thepistoncan be adjusted. For example, if-valve 61- isv closed` more than Valve 66v fluid will be-exhausted -from .the lower ends ofthe -pistonsslowerthan it will beexhausted fromA the-upper end. Therefore the web willA be -movedinto the --oven slower than it will be moved out-of the oven.

A shield is provided in order to prevent the web passingaround roller ll4 from being subjected-to drectradiation of heat from the oven space between sidesllZA and 43. when the-roller lis in its upper position. The shield 10- is formed as a rectangular plate ofY heat insulating material lthat-is slightly larger than roller. 4, as shown in-Figure. Projections extend from the ends of the plate through extensions of slots 49- and 50, below roller 4; These projectionsare securely fastenedto the side plates -IZand I3.

It-is `intended that-solenoid 65-wil1 be connected with the-energiZing-circuit of the-press as was solenoid valve 54 which controls the supply of fuel to-the oven. In this fashion when the press is operating solenoid 65 will be-energized'andfthe piston-valve will be so adjusted -that-the-carriageist moved to-its lower position as-shownin'- the drawing,land the web Will bein-the ovenlbeing dried. When, however,A the press is.` stoppedsolenoidv 55 will be de-energized and the piston-valve will-be moved to its lower position by spring-V53;- At thistime fluid will be admitted to the -lower endof athe cylinders 34- and 35 jand the carriageA will be moved upwardly to carry the web-outf-of the oven.

In FigureVv l-,there is. shown schematically one way-of controlling the pressdrive meansf which vis indicated as amotor. 53, along with valve54 and valvejl; There is shown a normallyopen so1e. noid Switch 2zwhich. isclosed against-.the .force ojasprlng by a solenoid coil 20d. Thevgsolenoid coil connected across theV-line-and.iSv-energized or--defenergized by*A the closing or openings-of a manually operated switch 28h. Mounted onthe plunger of', switch 20. is one-.pairof contacts 53a in the wires leading to press motor 53. There is alsd provided a second pairof-contactsa in the wiresleadingto,solenoid 65. and valve 5L Thus., when the. press drive `motor is Started. the. supply ofytfuel. to the ovenk will be turnedon andthe loop,` ofjweb around roller 41willbe moved into theoven ataspeed determined by theaddllsti mentof .valve 61j.

' Manualoperation ofgsolerioid. 65 may alsobe accomplished at any time when for some reason itmismeoessa-ry toamove-carr-iage Siindependentlys off-the operationofthe press; Toithisaendlthere. iselocatedacross thel leads-.to .solenoid"2 65a an `.energizing circuit includ-ing a -manual1y.-., operated? switchbthatnwhen closedzcan-.be usedtonener-J gizethe'solenoid'f-byrconnecting:-it.directly-tothe: line.- Thereis-..a1soprovided1 ay switchf-.69Lin-.thecircuit for solenoid.y :65 iwhich'. is normallyo closedeK This switch:A can besopenedamanually. atanyftime; however,- in order` to de-energize.- solenoid-1 651and2, to-permit the carriage to move-upwardly. to -br-ing; the-web-out ofi-the. oven,4 if-v ior. any` reason .this-l shouldi be desired during-the-time the -pressfis-firr operation.-

Assuming-that thepress has-been stopped; sol'ew noi'd valve 454. is closed :so-that. only Aa small amountf of@ gasissupplied-:-tof-the bur-ners.- in the oventhroug-h; by--pass-` 55;` with the.. result that'.i the oven- .iswarm but is-notsupplying enoug'l'r-heat to-dry a web. During the: time that. the-press: isfstopped solenoid-65 iscle-energized andthe pisi-I ton-l .valve- 511 is-inw its lowerposition-so that-fthe c-arriageds-A raised to-bringV ther-web outzottlic` oven.4 In .this position the web may easily-be threaded-.in vthe--press-without the necessity ofi-an-l operatorrunning the web through -theovenl- V/hen the-press hasr been threadedand/ everythe :pistonA valve 5&- to its upper positioni This permits iluid to flow through-pipe 58 and-pipe--Sllv to-the:` upperend-ofthe cylinders Stand-35;l There-fore .thecarriage B-will be moved-downwardly-to decrease the-size of the -web -looparound roller 5* and: increase the -size--ofthe-web loop around-roller Il atfarate -de-pendent--uponthe ad*Y justmentf of vvalve-61; Thisvalvemay be so adjusted #thaty by-V the-- time the carriage-reaches its-lower--position-i shown in Figure-1, the-oven will have-reachedl its normal operating temperature andV the web will be properly dried as 'it -isr being movedL through the furnace.' When the press-stops solenoids 54- and-65-will` be de-ener# g-igzedv to `cutY down Y the -fuellto the u oven` ande-to move-theweb upwardly out'off-theheat; decreesing-thesize of the loop-around roller -4 and-increasing the size of --the lcoparound roller-5.-

From Athe above description it will be seenthat theentiredryingunit-is compact and'occupies a relativelyA small space thatcan be obtained in the average printingpress.V Because of the` factth'at the web is driedwhile moving *bothdownwardly and upwardlyinaloop only-a short oven isinecesfsary. Thev same amount Aof heat-can befapplijed when drying the webi as it;,moves in two direc-g tions`that'couldbe-obtained with a longjpven that islocated'on one side only of the web. It is1only` necessary to use the gburnersin onepanel, .howeever',V if` theyl produce all of the heatl requiredi'for a@ given. operation.; Sincer rollers' 4 andV 5 V.are both mounted on the carriage andgmovefinunii son'the; tota-l- Aamount o1?` web thatis passing throughv thedryer-w-i-ll fnot bevaried-Ias the; car riagel is moved` fromone position tog, another'r' Therefore neither theregister ofgthe web" norits tension will be disturbedduetomoVement-ofrthe carriagewhilel bringing theweb Lin-to `andoutiof the oven. While the en-tire` dryer'- mechanism hasbeen4 shown mounted'for opera-tion in a-verf ticalf direction,v itwillbe; apparent thatit could be just'aseasilymountedeforroperation-ina horl 1, zontal direction. This will depend upon the construction of the machine with which it is used. vIn the above described embodiment of the invention the loops of web are moved in a single direction. In some cases it may not be possible to obtain the necessary space for this operation. In such cases an arrangement similar to that shown in Figure 4 may be used where the Slack for the loop moved out of the oven is taken up at an angle to the oven. Referring to that figure, it will be seen that the web W passes into the oven as a loop around the roller 1| and back upwardly over the water cooled rollers 1 and 8. In its path of travel the web passes on opposite sides of second roller 12 that is in line with the loop. Roller 1| is mounted in a carriage that comprises journals 13 located at each end thereof. which have threaded portions that are received on threaded shafts 14, only one of which is shown. These shafts extend in a vertical direction and are mounted for rotation in bearings 15. Roller 12 is mounted on a shaft which is received in journals 16 that are threaded to horizontally extending threaded shafts 11, only one of which is shown. These latter shafts are mounted for rotation in bearings 18. The shafts 14 and 11 are moved simultaneously, to move rollers 1| and 12, by a motor 19 that may be connected directly to one shaft 18, as shown in the drawing, or may be connected to that shaft through a suitable clutch. Shaft 11 serves to drive shaft 14 at the same rate of rotation through bevel gears 8| and spur gears 82. Suitable gearing is provided to drive the threaded shafts on the other side of the device. It is noted that guide rollers 83 and 84 are provided to direct the web in a horizontal loop as roller 12 is moved to the right in the drawing. Motor 19 is controlled in its direction of rotation by a switch 8'5. This switch has a rod 86 upon which are mounted an upper contact bar 81 and a lower contact bar 88. The switch bar is moved in an upwardly direction by spring 92 and is moved downwardly by a core 89 of a solenoid coil 9|. This coil is connected in the circuit for the press operation as was coil 65 of the piston valve 51 of Figure l. Also connected in circuit with solenoid coil 9| is a switch 93 by means of which the solenoid can be energized independently of press operation, and a manually operated switch 94 by means of which the solenoid can be de-energized independently of press operation.

The operation of this dryer unit is substantially the same as that described above. Normally when the press is running the various rollers are in the positions shown in the drawing with the web passing through the oven to dry thel ink thereof. When the press stops or the solenoid 9| is de-energized for some other reason, contact bars 81 and 88 will move out of engagement with the lower contacts and into engagement with the upper contacts. This reverses the direction of rotation of motor 19 to move roller 1| upwardly and roller 12 to the right to the dotted line position shown. The web is therefore moved out of the oven so that burning of the web will not occur. It is noted that suitable limit switches can be incorporated in the motor -circuit to limit the amount of movement of the rollers 1| and 12 in either direction.

It will be seen that the embodiment of the invention disclosed in Figure 4 operates in exactly the same fashion as that shown in Figure 1 except that the loop of web which is created when the web is moved out of the oven is take'n up at an angle to the. oven. In'each case-the web is moved out of the oven to facilitate threading of,

the same through the press and to prevent buming of the web in the event that the press is stopped. In each case the length of web in the dryer unitis the same and the tension of the web is not altered at any time. It will be apparent that fluid means similar to that disclosed in Figures 1 to 3 may be used to move the rollers 1| Vand 12 of Figure 4 instead of the mechanical means shown therein, if it is so desired. Likewise the mechanical means used to move the rollers of Figure 4 may be used to move the carriage upon which the rollers 4 and 5 of Figure 1 are mounted, if it is so desired.

In each of the embodiments of the invention described above the two movable rollers over which the web passes have been mounted for movement together. This is believed to be the preferred type of operation. In some cases, however, it may be desirable to have the rollers over which the web travels moved independently. Such a construction is shown in Figure 5 wherein it is intended that the web shall pass around a vertically movable roller similar to roller 1| in Figure 4. In its travel the web passes on opposite sides of a roller 12a corresponding to roller 12. In this case roller 12a is mounted in journal blocks 16a that are slidable on shafts 11a, only one of which is shown. Roller 12a is biased toward the right .by a cable 95 which passes over a pulley 96 and has a weight 91 or some other constant force acting on its end.

This embodiment of the invention acts to reduce the size of one loop of web while the size of a second loop is increasing as does the other embodiments. Here, however, the two rollers whichl form the loops are not mechanically connected together. One of the rollers is moved by the application of power from a suitable source while the other is moved by a constantly acting force to take up or supply the necessary slack while maintaining the web under a constant tension.

While in accordance with the provisions of the statutes I have illustrated and described the best form of embodiment of my invention now known to me, it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of my invention, as set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. In a web heating device, the combination of 'an oven including a pair of oppositely disposed heating sections witha space between said sections and a narrow slot extending through opposite sides .of said oven at each end of said space, a roll of a size to be received in said space, a shaft for said roll extending through said slots, bearings for said shaft outside of said space, and means to move said bearings in the direction of said slot to bring said roll into and out of said space.

2. In a web heating device the combination of a iirst roller anda second roller over which the web is passed in a pair of loops, means to move simultaneously said rollers to increase the size of one loop and decrease the size of the other loop whereby the total length of web in said loops and the tension thereof will not be changed, an oven to heat said web, and means to locate -said-oven--in a position vtoireceivesaid-*first loop 3. -In a webheating device, 'the combination j-of -yaY firstroller,'asecnd'irollerythe web to be @heated -fbeing threaded 'faround 'said rollers to form a fpairof-loop'sfmeans to' mount Isaid rollers v#for movement through rpaths of fthe'same length,

.means :to J'move simultaneously 'said rollers Lthrough `said paths to l#lengt-hen 'one f loop 'while shortening the other, and vfan ove'nfo'r 'heating said web'ilocatedso'that one loop is moved into and out of heating relation with respect to said oven as it is 'lengthned "andshortened 4. In a web heating `device the combination of a carriage, means to mountsaid carriage l-for movement through a path, a .pair of rollers mounted for rotationin'sp'aced apart position on said'carriage, the Web'b'eirig threadedaround ifsaidr'oll'ers to forma-loop, means to move'said r-l'arriage 'through its path to slii'ft thepos'ition fsaidlcop, va web -heatirg'ldevicd and `means t'o 'mount said AdeviceYalongithep'a'th of travel of `:s'a'iiloop whereby .the Iweb inf-said loop will be -h'eate'd by As'aidheating device-'when inlone 'ipo'si- Tti'on thereof.

75. .In 'a 'web'.heating device, 'the combination of a frame, tracks on said frame, a carriage, guide rollers on said carriage received in said tracks, a web guiding roll on said carriage around which the web is passed in a loop, a cylinder mounted on said frame adjacent to each side of said carriage, a piston received in each cylinder with a piston rod extending therefrom, means to attach the outer ends of said piston rods to opposite sides of said carriage, means to control the flow of an actuating fluid to opposite ends of said cylinders to reciprocate said carriage and thereby move said loop, and an oven located in the path of movement of said loop whereby said loop will be moved into and out of said oven as said carriage is reciprocated.

6. In a web heating device, the combination of a carriage, means to mount said carriage for reciprocating movement, a pair of guide rolls mounted on said carriage and around which the web is to be threaded in a loop extending in the direction of carriage movement, a U-shaped oven having a space therein opening at one end thereof of a size to receive the roller on the carriage around which the web is looped, means to mount said oven in a position where said last-mentioned roll will be received in the space in said oven at one end of the movement of said carriage, and means to move said carriage from a position in which said roll is in said space to a position in which said roll is withdrawn therefrom.

7. In a web heating device the combination of an elongated carriage, means to mount said carriage for reciprocating movement, a first guide roller located near one end of said carriage, a second guide roller located near the opposite ends of said carriage, an exit roller mounted adjacent to said second guide roller when said carriage is at one end of its path of travel, the web being threaded from a point in line with the direction of travel of said carriage around s aid first roller and in an opposite direction around said second roller and in the first direction to pass around said exit roller whereby as said carriage is moved the position of the guide rollers will be changed without changing the length of the web passing around them, means forming a heating zone into which said rst roller is moved when said carriage is at said one end of its path of travel, and means te move said -carriage to `rbringsaid iirst'guide roller into `and -outfof said heating zone.

8. In a webheating device, the combination of `an oven comprising a U-shaped'structure with a pair `of opposed heating members forming the legsofthe U, said members forming an enlarged space with narrow slots at the edges thereof,

the slots extending inthe direction of said mem- `bers, a web vguiding roller having a shaft-projecting'from the ends thereof,said Iroller being of a size tobefreceived-in saidspace -with the ends of the shaftprojecting through said slots, mounting 1means for the ends rof'- said-shaft, and means to move said mounting'means to carry said-shaft througha path fromfa-position in which-said moved-into andfoutof the heating-zone between said members.

` 9.'In awe'b heatingidevice, thecombination of anA oven having'anopening therein, a'rst roller over which'the'web is tobe passed in a loop, n-a second'lroller normally located in a position-bel'tween rthe-sides of the.floop,means to movefsaid first roller into and out of the opening in said oven, means to move said second roller in a path at an angle to that through which said rst roller moves, and operating mechanism for said moving means to move said first roller into said opening and said second roller to its normal position or to move said first roller out of said opening and said second roller through its path away from said normal position.

l0. In a web heating device, the combination of a first pair of parallel threaded shafts, a first roller, bearing for said roller threadedly mounted on said shafts, a second pair of parallel threaded shafts extending at an angle to said first pair of shafts, a second roller, bearings for said second roller threadedly mounted on said second pair of shafts, means to rotate simultaneously said pairs of shafts to move said rollers along the same, the web to be dried being threaded around said rollers in a pair of loops that are increased and decreased in size respectively as said rollers are moved in opposite directions, and an oven located to receive one roller and the web passing around it as said roller is moved in a direction to increase the length of its loop.

11. In a web heating machine, the combination of a machine operating on the web, an oven to heat the web, guide means over which the web is threaded in a loop, means to move said guide means into said oven whereby the web loop will be heated and out of said oven, operating means to start and stop said machine, operating means for said means to move, and means to control simultaneously said two operating means whereby as said machine is started said means to move will carry said web loop into said oven and as said machine is stopped said operating means will carry said web loop out of said oven.

12. The method of moving a travelling web into and out of a heated zone which comprises passing the web while it is moving through a rst loop and a second loop, changing the lengths of said loops by increasing the length of one while decreasing the length of the other the same amount, and moving the first loop into a heated zone while it is increasing in length and out of said heated zone while it is decreasing in length.

13. The method of moving a travelling web into and out of a heating zone which comprises continuously feeding the web through a path that includes a rst and a second lop extending in different directions, increasing the size of the rst loop and simultaneously decreasing the size of the second loop the same amount, and passing the rst loop into a heated zone as Yit increases in -size and removing said rst loop from the heated zone as it decreases in size.

14. The method of moving a traveling web into and out of a heated zone which comprises passing the web in a rst loop extending in one direction Yand a second loop extending in a second direction, changing the lengths of the loops by simultaneously increasing the length of one loop while decreasingthe length of the other rthe salme amount, moving the rst loop into a heated zone while it is increasing in length and out of said heated zone while it is decreasing in length, and controlling the movement of said in a path from a position in said heating zone to a position outside of the same, a pair of spaced and parallel guide rollers on said carriage, a. stationary guide roller, the strip material passing in a pair of reversely directed loops around said pair of guide rollers on said carriage and said stationary guide roller, and means to move said carriage through its path to carry the strip material guided by the rollers thereon into and out of said heating zone.

KARL L. DIETRICH.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS 4Number Name Date 1,261,056 Pfohl Apr. 2, 1918 1,266,735 White May 21, 1918 1,731,055 Marchev Oct. 8, 1929 1,755,755 Winder Apr. 22, 1930 2,203,065 Schueler June 4, 1940 2,292,511 Ferm Aug. 11, 1942 2,417,011 Offen Mar. 4, 1947 2,422,651 Ayers June 24, 1947 

